ADE Authorization Problem

Hello,

A year ago I bought a book from online store. I read a little of it and recently I reinstalled my PC but I forgot to deauthorize the computer before doing this.

Now I installed ADE again and signed in with my Adobe ID and password but it show me this error: E_LIC_ALREADY_FULFILLED_BY_ANOTHER_USER
I talked to the online store from which I bought the ebook and they told me that this happens when you authorize computer without signing with Adobe ID.
Sadly I can't deauthorize the PC because it is reinstalled so please tell me what can I do about this problem.

Thank you very much!